1.0 Field of the Invention:
This invention relates generally to hair dye applicators, and more particularly to applicators for the continuous application of a hair dye to head hair of human beings either directly or indirectly from a reservoir for the hair dye.
2.0 Discussion of Related Art:
A comb for the continuous application of a liquid to the hair and scalp of animals or human beings is known (see EP 0 157 032). The comb comprises a hollow space in which a first absorbent material is accommodated to take up and store the liquid. A plurality of teeth of a second absorbent material, which project into the first absorbent material through openings in the hollow space, are in capillary communication with the first absorbent material holding the liquid in the hollow space. In this manner, the liquid can be applied to both the hair, and to the skin through the tips and side faces of the teeth. This comb is particularly suitable for the treatment of animals with insecticides or the like.
In the treatment of head hair of human beings with hair-cosmetic preparations, such as hair dyes and the like, the main object is to uniformly apply the treatment preparation to the hair in accordance with the particular length and thickness thereof, to ensure uniform dyeing of every hair. However, it has been found that the comb described in EP 0 157 032 does not satisfy these requirements and that hair cannot be uniformly dyed with this comb.
3.0 Summary of the Invention:
An object of the present invention is to provide an improved applicator with which the quantity of treatment preparation applied can be controlled in accordance with the length and thickness of the hair of the person being treated, and to further provide for the complete emptying of the treatment preparation from its storage reservoir.
In one embodiment of the invention, an improved applicator comprises a reservoir for hair dye including a first absorbent material within a tubular element and teeth of a second absorbent material inserted into the element for transfer of the hair dye from the reservoir to the teeth not in contact therewith, the reservoir being connected to a rotational mechanism. This arrangement ensures that the teeth are always adequately supplied with hair dye by the reservoir. The treatment volume is precisely controlled through control of the speed of rotation. Compared with a known capillary-active connection, which is only guaranteed when the teeth are in complete contact with the stored material, the teeth of the present invention are completely independently arranged separate from the stored material, and the hair dye is expelled from the reservoir solely by centrifugal force and projected against the teeth or rather the inner wall of the tubular element. In addition, the rotational movement provides for complete emptying of the stored material.
In a preferred embodiment of the invention, the rotation mechanism is formed by a motor, a gear and a reservoir holder. The actual rotational movement is produced by the motor and can be converted into the required speed via a gear mechanism.
In another embodiment, the motor is equipped with an electronic circuit. The rotational speed and hence the volume of liquid expelled from the reservoir can be precisely controlled through this electronic circuit, for insuring the exact amount of hair dye required is always expelled from the teeth.
In still another embodiment, the applicator is made particularly easy to handle by arranging the rotation mechanism in a housing adjoining the tubular element.
In yet another embodiment of the invention, the reservoir is formed by a plurality of individual reservoirs of the first absorbent material arranged outside the axis of rotation. In this manner, a larger amount of liquid is able to issue from the reservoirs compared with a single reservoir during the rotational movement.
In another practical embodiment of the invention, an annular seal is arranged between the tubular element and the reservoir holder. This seal ensures that no liquid hair dye is able to penetrate into the housing of the rotation mechanism.